Campagnolo's dérailleurs - up to the final era of their straight-parallelogram models in the mid 1990's - are rather unique in the fact that the basic design was essentially a long-term revision of the 1951 Gran Sport. As the image above shows (Gran Sport in blue, Nuovo Record in yellow, Super Record in red), each subsequent variant was little more then a slight revision of the Gran Sport's cage geometry and the pivot point in an effort to get the forward/upper pulley wheel to provide optimum chain gap in as many cogs as possible.
The other notable revision - applied to all three dérailleurs - is the angle at which they are designed to sit on a standard Campagnolo 1010/1010A dropout. Like the pulley cage, the parallelogram angle stop was revised on each model for the same reason that the cage was revised - to position the pulley wheels closer to the cogs and improve chain gap.
Super Record sits at approximately 125 degrees (in red), Nuovo Record at 115 degrees (mustard yellow), and Gran Sport at 95 degrees (blue); as indicated below:
Ironically enough, Campagnolo's mid-range, 1984 Victory rear dérailleur - which shared the same essential geometry with Super Record - was fitted with a user-adjustable pivot stop which allowed the dérailleur to be positioned at Nuovo Record's 115 degree setting, Super Record's 125 degrees, or an astounding 135 degrees; the latter most ideal for narrow gear clusters with little variance between cog sizes - and very effective at that.
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